TM 10-3930-675-20-1 0006 00-23 TROUBLESHOOTING PROCEDURES (NON-ERROR CODE) - CONTINUED 0006 00 Table 7. Boom System Troubleshooting Procedures (Non-Error Code) - Continued. MALFUNCTION TEST OR INSPECTION CORRECTIVE ACTION 2. Boom Will Not Extend or Retract Properly - Continued. 4.  Check extension cylinder hydraulic  lines  and  hoses  for damage and signs of leakage. a.  Tighten loose connections. b.  Replace  damaged  or  leaking lines and hoses (WP 0180 00). 5.  Check wear plates for excessive wear and damage. Replace    excessively   worn   or damaged wear plates (WP 0139 00). 6.  Test  boom  system  operating pressure  (WP  0186  00,  test point no. 8). Operating pressure  should  be  3480  psi (240 bar). a.  Notify   DS   Maintenance   to replace    boom    and    brake system   hydraulic   pump   if pressure is not as specified. b.  Notify   DS   Maintenance   to replace   boom   control   valve assembly. 7.  Check boom extension calibration settings (WP 0197 00). Calibrate    boom    extension    as required (WP 0197 00). 3.   Boom Folding Cylinders Not Working. 1.  Inspect boom folding cylinders    for    damage    and signs of leakage. Notify     DS     Maintenance     to replace    damaged    or    leaking boom folding cylinder(s). 2.  Inspect  boom  folding  control valves for damage and signs of leakage. Replace    damaged    or    leaking boom   folding   control   valve(s) (WP 0170 00). 3.  Check  boom folding cylinder hydraulic  lines  and  hoses  for damage and signs of leakage. a.  Tighten loose connections. b.  Replace  damaged  or  leaking lines and hoses (WP 0180 00). 4.  Check cab position proximity switches for obstructions, damage, and proper adjustment. Clean,   replace   or   adjust   cab position  proximity  switches  as required (WP 0075 00). 5.  Test  boom  system  operating pressure  (WP  0186  00,  test point     no.     11).     Operating pressure  should  be  3045  psi (210 bar). a.  If   operating   pressure   is   as specified, replace over-center control valve (WP 0180 00). b.  Notify   DS   Maintenance   to replace     boom     and     brake system    hydraulic    pump    if pressure is not as specified.